Definición de critical mass en inglés:

sustantivo

Just two months earlier, the Observer published internal documents indicating that there had been eight breaches of safety rules intended to prevent critical masses of fissile material being brought together.

Its basic principle is assembling a critical mass of a radioactive element with properties to spark a swift chain reaction.

Such explosions are caused by the accumulation of a critical mass of material falling onto the neutron star from a partner.